Forerunners of Mammals

Description

The evolution and paleobiology of the synapsids

About 320 million years ago a group of reptiles known as the synapsids emerged and forever changed Earth's ecological landscapes. This book discusses the origin and radiation of the synapsids from their sail-backed pelycosaur ancestor to their diverse descendants, the therapsids or mammal-like reptiles, that eventually gave rise to mammals. It further showcases the remarkable evolutionary history of the synapsids in the Karoo Basin of South Africa and the environments that existed at the time. By highlighting studies of synapsid bone microstructure, it offers a unique perspective of how such studies are utilized to reconstruct various aspects of biology, such as growth dynamics, biomechanical function, and the attainment of sexual and skeletal maturity. A series of chapters outline the radiation and phylogenetic relationships of major synapsid lineages and provide direct insight into how bone histological analyses have led to an appreciation of these enigmatic animals as once-living creatures. The penultimate chapter examines the early radiation of mammals from their nonmammalian cynodont ancestors, and the book concludes by engaging the intriguing question of when and where endothermy evolved among the therapsids.

Preface
Acknowledgments
List of Contributors
1. The Origin and Radiation of Therapsids \ Tom S. Kemp
2. Therapsid Biodiversity Patterns and Paleoenvironments of the Karoo Basin, South Africa \ Roger Smith, Bruce Rubidge, and Merrill van der Walt
3. The Microstructure of Bones and Teeth of Nonmammalian Therapsids \ Anusuya Chinsamy-Turan
4. The Paleobiology and Bone Microstructure of Pelycosaurian-Grade Synapsids \ Adam K. Huttenlocker and Elizabeth Rega
5. Dicynodont Growth Dynamics and Lifestyle Adaptations \ Sanghamitra Ray, Jennifer Botha-Brink, and Anusuya Chinsamy-Turan
6. Biological Inferences of the Cranial Microstructure of the Dicynodonts Oudenodon and Lystrosaurus \ Sandra C. Jasinoski and Anusuya Chinsamy-Turan
7. Bone and Dental Histology of Late Triassic Dicynodonts from North America \ Jeremy L. Green
8. Bone Histology of Some Therocephalians and Gorgonopsians, and Evidence of Bone Degradation by Fungi \ Anusuya Chinsamy-Turan and Sanghamitra Ray
9. The Radiation and Osteohistology of Nonmammaliaform Cynodonts \ Jennifer Botha-Brink, Fernando Abdala, and Anusuya Chinsamy-Turan
10. The Radiation, Bone Histology, and Biology of Early Mammals \ Jørn H. Hurum and Anusuya Chinsamy-Turan
11. The Evolution of Mammalian Endothermy \ John A. Ruben, Willem J. Hillenius, Tom S. Kemp, and Devon E. Quick
References
Index

Sujets

• Sciences de la nature
• Biologie
• Life Sciences
• Fossils
• Sciences et techniques
• Biology
• Rock (geology)
• Paleontology
• Evolution
• 454 Life Sciences
• Rocks
• Science

Informations

• Publié par: Indiana University Press
• Date de parution: 18 novembre 2011
• Nombre de lectures: 0
• EAN13: 9780253005335
• Langue: English
• Poids de l'ouvrage: 4 Mo

Extrait

FORERUNNERS OF MAMMALS
Life of the Past James O. Farlow, editor
FORERUNNERS OF MAMMALS
Radiation Histology Biology

Edited by Anusuya Chinsamy-Turan
Indiana University Press
Bloomington and Indianapolis
This book is a publication of
Indiana University Press
601 North Morton Street
Bloomington, Indiana 47404-3797 USA
iupress.indiana.edu
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2012 by Indiana University Press
All rights reserved
No part of this book may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and recording, or by any information storage and retrieval system, without permission in writing from the publisher. The Association of American University Presses Resolution on Permissions constitutes the only exception to this prohibition.
The paper used in this publication meets the minimum requirements of the American National Standard for Information Sciences-Permanence of Paper for Printed Library Materials, ANSI Z39.48-1992.
Manufactured in the United States of America
Library of Congress Cataloging-in-Publication Data
Forerunners of mammals : radiation, histology, biology / edited by Anusuya Chinsamy-Turan.
p. cm. - (Life of the past)
Includes bibliographical references and index.
ISBN 978-0-253-35697-0 (cloth : alk. paper)
1. Reptiles, Fossil. 2. Mammals-Evolution. 3. Bones-Histology. I. Chinsamy-Turan, Anusuya.
QE861.F67 2012
567.9 3-dc23
2011016622
1 2 3 4 5 17 16 15 14 13 12
This book is dedicated to the memory of
JAMES W. KITCHING
(1922-2003)
Gondwanan Paleontologist
An Exceptional Fossil Hunter and an Inspiration to Many
Contents

Preface
Acknowledgments
List of Contributors
1 The Origin and Radiation of Therapsids
Tom S. Kemp
2 Therapsid Biodiversity Patterns and Paleoenvironments of the Karoo Basin, South Africa
Roger Smith, Bruce Rubidge, and Merrill van der Walt
3 The Microstructure of Bones and Teeth of Nonmammalian Therapsids
Anusuya Chinsamy-Turan
4 The Paleobiology and Bone Microstructure of Pelycosaurian-Grade Synapsids
Adam K. Huttenlocker and Elizabeth Rega
5 Dicynodont Growth Dynamics and Lifestyle Adaptations
Sanghamitra Ray, Jennifer Botha-Brink, and Anusuya Chinsamy-Turan
6 Biological Inferences of the Cranial Microstructure of the Dicynodonts Oudenodon and Lystrosaurus
Sandra C. Jasinoski and Anusuya Chinsamy-Turan
7 Bone and Dental Histology of Late Triassic Dicynodonts from North America
Jeremy L. Green
8 Bone Histology of Some Therocephalians and Gorgonopsians, and Evidence of Bone Degradation by Fungi
Anusuya Chinsamy-Turan and Sanghamitra Ray
9 The Radiation and Osteohistology of Nonmammaliaform Cynodonts
Jennifer Botha-Brink, Fernando Abdala, and Anusuya Chinsamy-Turan
10 The Radiation, Bone Histology, and Biology of Early Mammals
J rn H. Hurum and Anusuya Chinsamy-Turan
11 The Evolution of Mammalian Endothermy
John A. Ruben, Willem J. Hillenius, Tom S. Kemp, and Devon E. Quick
References
Index
Preface

This book brings together a group that has over many years researched various aspects of the evolution and paleobiology of the synapsids. Many of us have collaborated in our research endeavors, and all of us have at some stage shared information and had many hearty discussions about the biology of our distant relatives.
The book comprises eleven chapters. The first two chapters provide an introduction to the predecessors of mammals and their relatives, and an assessment of the ancient world in which they radiated. The opening chapter sets the scene, providing a guide of who the synapsids were and how they are related to one another. In this chapter, Tom Kemp provides an up to date assessment of the radiation of the synapsids from their earliest pelycosaur members, to the diverse nonmammalian therapsids, and later to the increasingly more mammal-like cynodonts. All this is done from a global perspective.
The second chapter of this book deals more specifically with the Karoo Basin of South Africa and documents an unparalleled track record of the evolution and radiation of the therapsids. Here, Karoo paleontologists, Roger Smith and Bruce Rubidge, together with a recent PhD graduate Merrill van der Walt, provide a unique perspective of therapsid biodiversity and paleoenvironmental analysis of the Karoo Basin of South Africa. For the first time, faunal turnover in the Karoo Basin is provided through a lens of absolute numbers of genera and have permitted detailed trophic level analyses for each of the biozones.
The third chapter by yours truly sets the scene for the bone microstructure chapters that follow. The first part of this chapter takes the form of an atlas of bone microstructure that will enable a novice to identify particular types of bone tissues in synapsids. The second part examines the biological implications of particular types of bone microstructures and how these can be utilized to deduce various aspects of the biology of extinct animals.
The next seven chapters focus on particular synapsid lineages. Each of these chapters is structured to provide a phylogenetic and paleobiological context before delving into the bone microstructure of that particular group. The first in this series of chapters ( chapter 4 ) predictably deals with the earliest members of the Synapsida, the pelycosaurs. Here, Adam Huttenlocker and Elizabeth Rega present an overview of the bone microstructure of pelycosaurian-grade synapsids from both normal and pathological skeletal elements.
The fifth chapter is by Sanghamitra Ray, my former postdoctoral fellow, Jennifer Botha-Brink, my former PhD student, and me. Here we review what is known about the bone microstructure of the dicynodonts, which were the dominant herbivores of the Permian. We then focus on a selection of basal to more derived dicynodont taxa from South Africa and India in the interest of deciphering growth patterns through the Dicynodontia.
The sixth chapter by Sandra Jasinoski, my current postdoctoral fellow, and myself, presents the first comprehensive assessment of dicynodont cranial microstructure. Besides documenting intercranial element variability in histology, we also assess whether functional signatures are recorded in the cranial microstructure.
The seventh chapter is by Jeremy Green, who provides an assessment of the bone and tusk microstructure of large Late Triassic dicynodonts from North America. Here he provides a comparative assessment of the bone microstructure of Placerias , a Kannemeyeriiform, and another large as yet unnamed dicynodont, as well as a detailed account of the growth increments recorded in the tusks.
The eighth chapter is by Sanghamitra Ray and me. Here we review the bone microstructure of some therocephalians and gorgonopsians, and we present novel data pertaining to bone damage caused by fungi in Permian-aged bones. This chapter also highlights the importance of extensive sampling of skeletal elements to appreciate histovariability within and between bones.
Chapter nine, by Jennifer Botha-Brink, Fernando Abdala, and me, reviews the bone microstructure of the nonmammaliaform cynodonts and presents fresh data on four additional taxa from South Africa and two from Brazil.
J rn Hurum and I review the bone microstructure of early mammals from the United Kingdom and Mongolia in chapter ten, and we provide new data pertaining to the bone microstructure of extant monotremes, marsupials, and placentals.
The final chapter brings together for the first time three physiologists, John Ruben, Willem Hillenius, and Devon Quick, and paleontologist Tom Kemp, who provide an interesting perspective on when and how endothermy evolved among the synapsids.
From this book it is evident that even though the dicynodonts are relatively well-studied, many questions still exist such as their particular lifestyle and growth dynamics. The same could be said for the cynodonts, while the therocephalians and gorgonopsians are comparatively less well-studied. However, of all the therapsids, least is known about dinocephalians, which may be a direct result of the fact that their taxonomy has been so problematic. However, recent work has resolved some of these problems and plans are afoot to fill in this gap.
This unique book on the radiation, histology, and biology of the synapsids provides a documentation of the bone microstructure of the forerunners of mammals and insights into their biology, as well as highlights areas for future research.
Acknowledgments

Having just completed a book on dinosaur bone microstructure, the notion of another book was furthest from my mind when Jim Farlow seeded the idea of a book on therapsid bone in my head. Once implanted, it simply grew and has now materialized. Thanks, Jim!
I am indebted to all the contributors to this book. The successful completion of an edited volume of this nature is directly attributable to the hard work and diligence of the entire team. I count myself as incredibly fortunate to have had the opportunity to collaborate with all of you at some stage in the past, and now again on this book. Bob Sloan, Jim Farlow, Bernadette Zoss, Dan Pyle, June Silay, Karen Hallman, and others at Indiana University Press, thank you for dealing with my queries so efficiently.
I am grateful to all the collection managers from around the world who grant permission for histological analyses of fossils under their curation because they understand and appreciate the importance of studies of bone microstructure. Kholeka Sidinile, Kerwin von Willig, and especially Andrea Plos are acknowledged for technical support.
Over the years, I ve had the opportunity of learning and growing with several research students, and currently, I have an exceptional group of postdoctoral fellows in my lab-Romala Govender, Sandra Jasinoski, Daniel Thomas, Yasemin Tulu, and, more recently, Aurore Canoville-as well as graduate students Nicholas Fordyce,